U.S. patent application number 12/230594 was filed with the patent office on 2009-09-03 for system and method for dynamic braking a vehicle closure system.
Invention is credited to Tomasz T. Dominik, Thomas P. Frommer.
Application Number | 20090222174 12/230594 |
Document ID | / |
Family ID | 40387937 |
Filed Date | 2009-09-03 |
United States Patent
Application |
20090222174 |
Kind Code |
A1 |
Frommer; Thomas P. ; et
al. |
September 3, 2009 |
System and method for dynamic braking a vehicle closure system
Abstract
A system for dynamic braking a vehicle closure including a drive
mechanism mounted to the vehicle, the drive mechanism having
contacts to receive a drive signal to cause the drive mechanism to
move the vehicle closure between an open and a close position in
response to the drive signal, the drive mechanism capable of
generating a generated drive signal during at least a portion of
the vehicle closure from the open to the close position; and a
controller having electrical outputs electrically coupled to the
electrical contacts of the drive mechanism and electrical inputs to
provide the drive signals to the drive mechanism and to receive
generated drive signals from the drive mechanism, the controller
configured to provide the generated drive signals back to the drive
mechanism during operation of the vehicle closure to provide
dynamic braking of the vehicle closure from the open to the close
position.
Inventors: |
Frommer; Thomas P.; (Mount
Albert, CA) ; Dominik; Tomasz T.; (Toronto,
CA) |
Correspondence
Address: |
PATTON BOGGS LLP
2550 M STREET NW
WASHINGTON
DC
20037-1350
US
|
Family ID: |
40387937 |
Appl. No.: |
12/230594 |
Filed: |
September 2, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60935770 |
Aug 30, 2007 |
|
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|
Current U.S.
Class: |
701/49 ;
296/146.4 |
Current CPC
Class: |
E05Y 2201/24 20130101;
E05Y 2400/302 20130101; B60J 7/16 20130101; E05Y 2201/214 20130101;
E05F 15/77 20150115; E05Y 2800/112 20130101; B60J 5/101 20130101;
E05Y 2201/41 20130101; E05F 15/70 20150115; E05Y 2201/21 20130101;
E05Y 2400/336 20130101; E05Y 2900/548 20130101 |
Class at
Publication: |
701/49 ;
296/146.4 |
International
Class: |
G06F 17/00 20060101
G06F017/00; E05F 15/20 20060101 E05F015/20 |
Claims
1. A system for dynamic braking a vehicle closure of a vehicle,
comprising: a drive mechanism mounted to the vehicle, the drive
mechanism having electrical contacts to receive a drive signal to
cause the drive mechanism to move the vehicle closure between an
open and a close position in response to the drive signal, the
drive mechanism capable of generating a generated drive signal
during at least a portion of the operation of the vehicle closure
from the open to the close position; and a controller having
electrical outputs electrically coupled to the electrical contacts
of the drive mechanism and electrical inputs to provide the drive
signals to the drive mechanism and to receive generated drive
signals from the drive mechanism, the controller further configured
to provide the generated drive signals back to the drive mechanism
during operation of the vehicle closure to provide dynamic braking
of the vehicle closure from the open to the close position.
2. The system for dynamic braking a vehicle closure according to
claim 1, wherein the drive mechanism is a motor capable of
generating the generated drive signals during the operation of the
vehicle closure from the open to the close position.
3. The system for dynamic braking a vehicle closure according to
claim 1, wherein the controller further comprises: a circuit board
having a plurality of microcontrollers for controlling the drive
mechanism between one of an open position, a close position, a
freewheeling operation, and the dynamic braking operation.
4. The system for dynamic braking a vehicle closure according to
claim 1, wherein the controller further comprises: a processor
executing a software program that alters the drive signal in
response to the position of the vehicle closure.
5. The system for dynamic braking a vehicle closure according to
claim 4, wherein the software program is configured to determine
when to apply the drive signal to the drive mechanism based on one
of speed and position of the vehicle closure.
6. The system for dynamic braking a vehicle closure according to
claim 4, wherein the software program is further configured to
provide the drive signal generated by the drive mechanism back to
the drive mechanism during the operation of the vehicle closure
from the open to the close position.
7. The system for dynamic braking a vehicle closure according to
claim 1, wherein the vehicle closure is a lift gate.
8. The system for dynamic braking a vehicle closure according to
claim 1, further comprising: a vehicle closure position sensor
mounted on the vehicle in communication with the controller for
providing to the controller data relating to the closing velocity
of the vehicle closure relative to the vehicle.
9. The system for dynamic braking a vehicle closure according to
claim 1, wherein the vehicle closure position sensor is one of a
rotary flex shaft encoder, Hall Effect sensor, and angle
sensor.
10. A method for dynamic braking a vehicle closure of a vehicle,
comprising: generating a generated drive signal by a drive
mechanism under mechanical force of kinetic energy from the vehicle
closure during at least a portion of the operation of the vehicle
closure from an open position to a close position; and feeding back
the generated drive signal to the drive mechanism for dynamic
braking of the vehicle closure during the at least a portion of the
operation of the vehicle closure from the open position to the
close position.
11. The method for dynamic braking a vehicle closure according to
claim 10, further comprising: determining a speed of the vehicle
closure relative to the vehicle.
12. The method for dynamic braking a vehicle closure according to
claim 11, wherein feeding back the generated drive signal further
comprises: pulse width modulating the generated drive signal to the
drive mechanism.
13. The method for dynamic braking a vehicle closure according to
claim 12, wherein pulse width modulating the generated drive signal
to the drive mechanism further comprises: increasing the pulse
width modulation generated drive signal to increase the dynamic
braking and decrease the speed of the vehicle closure.
14. The method for dynamic braking a vehicle closure according to
claim 12, wherein pulse width modulating the generated drive signal
to the drive mechanism further comprises: decreasing the pulse
width modulation generated drive signal to decrease the dynamic
braking and increase the speed of the vehicle closure.
15. The method for dynamic braking a vehicle closure according to
claim 10, wherein pulse width modulating the generated drive signal
to the drive mechanism further comprises: decreasing the pulse
width modulation generated drive signal to decrease the dynamic
braking and increase the speed of the vehicle closure.
16. A vehicle having a vehicle closure, comprising: a vehicle body,
the vehicle closure being operably mounted to the vehicle body to
enable the vehicle closure to move between an open and a close
position; a drive mechanism operably mounted to the vehicle and the
vehicle closure, the drive mechanism having electrical contacts to
receive a drive signal to cause the drive mechanism to move the
vehicle closure between the open and the close position in response
to the drive signal, the drive mechanism capable of generating a
generated drive signal during at least a portion of the operation
of the vehicle closure from the open to the close position; and a
controller having electrical outputs electrically coupled to the
electrical contacts of the drive mechanism and electrical inputs to
provide the drive signals to the drive mechanism and to receive
generated drive signals from the drive mechanism, the controller
further configured to provide the generated drive signals back to
the drive mechanism during operation of the vehicle closure to
provide dynamic braking of the vehicle closure from the open to the
close position.
17. The vehicle having a vehicle closure according to claim 16,
wherein the drive mechanism is a motor capable of generating drive
signals during the operation of the vehicle closure from the open
to the close position.
18. The vehicle having a vehicle closure according to claim 16,
wherein the controller further comprises: a circuit board having a
plurality of microcontrollers for controlling the drive mechanism
between one of an open position, a close position, a freewheeling
operation, and the dynamic braking operation.
19. The vehicle having a vehicle closure according to claim 16,
wherein the controller further comprises: a processor executing a
software program that alters the generated drive signal in response
to the closing velocity of the vehicle closure.
20. The vehicle having a vehicle closure according to claim 19,
wherein the software program is configured to determine when to
apply a generated drive signal to the drive mechanism based on the
closing velocity of the vehicle closure.
21. The vehicle having a vehicle closure according to claim 20,
wherein the software program is further configured to provide a
generated drive signal generated by the drive mechanism back to the
drive mechanism during the operation of the vehicle closure from
the open to the close position.
22. The vehicle having a vehicle closure according to claim 16,
wherein the vehicle closure is a lift gate.
23. A controller for dynamically braking a vehicle closure,
comprising: a processor configured receive a control signal
representative of a closing velocity of the vehicle closure, the
processor configured to receive a generated drive signal from a
drive mechanism controlling the vehicle closure; software
executable by the processor, the software configured to generate a
pulse width modulation generated drive signal in response to the
generated drive signal; and an input/output unit configured to
communicate the pulse width modulation generated drive signal to
the drive mechanism for providing dynamic braking to the vehicle
closure.
24. The controller for dynamically braking a vehicle closure
according to claim 23, wherein the controller further comprises: a
first microcontroller circuit operable between an on position and
an off position, the first microcontroller circuit in contact with
a power source for providing an opening drive signal to the drive
mechanism.
25. The controller for dynamically braking a vehicle closure
according to claim 23, wherein the controller further comprises: a
second microcontroller circuit operable between an on position and
an off position, the second microcontroller circuit in contact with
the power source for providing a closing drive signal to the drive
mechanism.
26. The controller for dynamically braking a vehicle closure
according to claim 23, wherein the controller further comprises: a
third microcontroller circuit operable between an on position and
an off position, the third microcontroller circuit for providing
the pulse width modulation generated drive signals.
27. The controller for dynamically braking a vehicle closure
according to claim 23, wherein the controller further comprises: a
fourth microcontroller circuit operable between an on position and
an off position, the fourth rmicrocontroller circuit in contact
with the controller for providing the dynamic braking to the
vehicle closure.
Description
RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Patent Application No. 60/935,770 filed on Aug. 30, 2007, the
entire teachings of which are incorporated herein by reference.
BACKGROUND
[0002] Vehicles have become more and more automated to accommodate
the desires of consumers. Vehicle parts, including windows, sun
roofs, seats, sliding doors, and lift gates (e.g., rear latches and
trunks) have been automated to enable users to press a button on
the vehicle or on a remote control to automatically open, close, or
otherwise move the vehicle parts.
[0003] When a vehicle closure system, such as a lift gate is
elevated off the ground or from a closed position on a vehicle,
some method is utilized to hold it up. As it is held above the
ground or above a closed position of a vehicle, the mass of the
lift gate under the influence of gravity equates to a substantial
amount of weight and potential energy in the downward direction
toward the closed position. When the closure system or lift gate is
released from an open or held position, it travels downward to the
closed position. Typically, sensors are employed to determine the
actual position of the lift gate for determining the speed of the
lift gate and whether it needs to be controlled or not in order to
prevent the lift gate from slamming closed and possibly injuring
the operator.
[0004] Several different types of sensors may be employed to
determine the position and speed of a closing vehicle closure, such
as Hall Effect sensors or optical vane interrupt sensors. One
problem with the use of Hall Effect sensors or optical vane
interrupt sensors is mechanical backlash due to system flex and
unloaded drive mechanism conditions. As an example, when a lift
gate is closing, the gate reaches a point where the weight of the
lift gate begins to close the lift gate without any additional
effort from the drive mechanism. In fact, at this point, the drive
mechanism may apply effort to the lift gate to prevent premature
closing. This is a state when negative energy is imparted from the
drive mechanism to the lift gate.
[0005] The negative energy applied by the motor on the lift gate is
used to control the downward velocity of the vehicle closure. For
example, if a lift gate is closing too quickly, then a closed loop
control algorithm instructs the controller to reduce the power
applied to the motor or drive system until the desired velocity is
achieved. Conversely, if the lift gate is closing too slowly, then
the closed loop control algorithm instructs the controller to
increase the power applied to the motor or drive system until the
desired velocity is achieved. In either case, these conventional
systems require additional power input into the motor to decrease
or increase the closing speed of the vehicle closure.
[0006] Another problem associated with conventional lift gate
closure systems is the substitution of conventional lift gate
struts with power struts. Typically, conventional lift gate struts
are simpler mechanical systems that require a smaller footprint or
area for operation. As these are being replaced with motorized
systems, such as motorized struts, the motorized struts are being
designed to fit into the area or footprint typically occupied by
the conventional struts. The desire to fit a motorized strut or
system into the footprint or area of a conventional strut creates a
size constraint for their gear train to be made as efficient as
possible and their motor to be of a reduced size. Accordingly,
these smaller gear trains and motors are less able to handle the
forces of conventional closures apparatuses, such as lift gates,
when the lift gates are accelerating closed due to gravity, thus
causing the lift gates to slam closed.
SUMMARY
[0007] The above-described problems are solved and a technical
advance achieved by the system and method for dynamic braking a
vehicle closure system ("dynamic braking system") disclosed in this
application. The present dynamic braking system controls the speed
of a vehicle closure without the additional input of external power
to the motor from a power source during the closing operation.
Instead, the power generated from the kinetic energy of the vehicle
closure during a closing operation is harnessed by the present
dynamic braking system to then control the velocity of the vehicle
closure during the closing operation. The present dynamic braking
system captures the kinetic energy from the closing lift gate
through the motor to create electrical energy to be used by the
present dynamic braking system and then to utilize this energy to
apply a "braking effect" to the motor without the need of
additional power from the power supply.
[0008] The motor of the present dynamic braking system generates
electrical energy as a result of having kinetic energy applied to
it. As the closure moves, the motor is turned and electrical energy
is generated. To provide for improved speed control and obstacle
protection, the present dynamic braking system utilize direct
sensing of the position of the lift gate and feeds that information
to a controller having configurable circuitry to accommodate
different vehicle closures on different systems. The present
dynamic braking system provides for the generated electrical energy
to be fed back into the dynamic braking system to be utilized to
brake the closure's closing velocity without the need for
additional energy being applied to the dynamic braking system,
while providing a safe, controlled descent or closing operation.
The dynamic braking system may raise and lower a vehicle closure,
such as a lift gate, in accordance with user commands, typically
given via a remote control device or push button. Also, the present
dynamic braking system further provides improved pinch forces.
Without additional power being added to the dynamic braking system,
there is less energy that will be released/transferred to an object
that may be being pinched by the closing of a lift gate. For
example, conventional systems expose an object that is located
between a lift gate and the body of a vehicle to the full force or
momentum of the lift gate as the driving force is being applied by
the drive system. Conversely, the present dynamic braking system
only exposes an object to the reduced momentum of the lift gate as
it is being operated. As there is no additional power or drive
force exerted by the present dynamic braking system it regulates
and reduces the momentum of the gate, and thus any pinching
forces.
[0009] In one aspect, the present dynamic braking system includes a
drive mechanism mounted to the vehicle, the drive mechanism having
electrical contacts to receive a drive signal to cause the drive
mechanism to move the vehicle closure between an open and a close
position in response to the drive signal, the drive mechanism
capable of generating a generated drive signal during at least a
portion of the operation of the vehicle closure from the open to
the close position; and a controller having electrical outputs
electrically coupled to the electrical contacts of the drive
mechanism and electrical inputs to provide the drive signals to the
drive mechanism and to receive generated drive signals from the
drive mechanism, the controller further configured to provide the
generated drive signals back to the drive mechanism during
operation of the vehicle closure to provide dynamic braking of the
vehicle closure from the open to the close position.
[0010] In one aspect, the drive mechanism is a motor capable of
generating the generated drive signals during the operation of the
vehicle closure from the open to the close position. Additionally,
the controller may include a circuit board having a plurality of
microcontrollers for controlling the drive mechanism between one of
an open position, a close position, a freewheeling operation, and
the dynamic braking operation. Also, the controller may include a
processor executing a software program that alters the drive signal
in response to the position of the vehicle closure. The software
program may be configured to determine when to apply the drive
signal to the drive mechanism based on the position of the vehicle
closure. Further, the software program is further configured to
provide the drive signal generated by the drive mechanism back to
the drive mechanism during the operation of the vehicle closure
from the open to the close position.
[0011] In one embodiment, the vehicle closure is a lift gate. The
dynamic braking system may include a vehicle closure position
sensor mounted on the vehicle in communication with the controller
for providing to the controller data relating to the closing
velocity of the vehicle closure relative to the vehicle. The
vehicle closure position sensor may be one of a rotary flex shaft
encoder and a Hall Effect sensor.
[0012] In another aspect, the present dynamic braking system
includes a method for generating a generated drive signal by a
drive mechanism under mechanical force of kinetic energy from the
vehicle closure during at least a portion of the operation of the
vehicle closure from an open position to a close position; and
feeding back the generated drive signal to the drive mechanism for
dynamic braking of the vehicle closure during the at least a
portion of the operation of the vehicle closure from the open
position to the close position. The method may further include
determining a speed of the vehicle closure relative to the vehicle.
Also, the method may include feeding back the generated drive
signal may include pulse width modulating the generated drive
signal to the drive mechanism.
[0013] In one embodiment, the pulse width modulating the generated
drive signal to the drive mechanism may further include increasing
the pulse width modulation generated drive signal to increase the
dynamic braking and decrease the speed of the vehicle closure. The
pulse width modulating the generated drive signal to the drive
mechanism may further include decreasing the pulse width modulation
generated drive signal to decrease the dynamic braking and increase
the speed of the vehicle closure.
[0014] In another aspect the present dynamic braking system
includes a vehicle having a vehicle closure, including a vehicle
body, the vehicle closure being operably mounted to the vehicle
body to enable the vehicle closure to move between an open and a
close position; a drive mechanism operably mounted to the vehicle
and the vehicle closure, the drive mechanism having electrical
contacts to receive a drive signal to cause the drive mechanism to
move the vehicle closure between the open and the close position in
response to the drive signal, the drive mechanism capable of
generating a generated drive signal during at least a portion of
the operation of the vehicle closure from the open to the close
position; and a controller having electrical outputs electrically
coupled to the electrical contacts of the drive mechanism and
electrical inputs to provide the drive signals to the drive
mechanism and to receive generated drive signals from the drive
mechanism, the controller further configured to provide the
generated drive signals back to the drive mechanism during
operation of the vehicle closure to provide dynamic braking of the
vehicle closure from the open to the close position.
[0015] In one embodiment, the drive mechanism is a motor capable of
generating drive signals during the operation of the vehicle
closure from the open to the close position. The controller may
further include a circuit board having a plurality of
microcontrollers for controlling the drive mechanism between one of
an open position, a close position, a freewheeling operation, and
the dynamic braking operation. Also, the controller may include a
processor executing a software program that alters the generated
drive signal in response to the closing velocity of the vehicle
closure. The software program may be configured to determine when
to apply a generated drive signal to the drive mechanism based on
the closing velocity of the vehicle closure. The software program
may be further configured to provide a generated drive signal
generated by the drive mechanism back to the drive mechanism during
the operation of the vehicle closure from the open to the close
position. In another embodiment, the vehicle closure is a lift
gate.
[0016] In another aspect, the present dynamic braking system
includes a controller for dynamically braking a vehicle closure,
including a processor configured receive a control signal
representative of a closing velocity of the vehicle closure, the
processor configured to receive a generated drive signal from a
drive mechanism controlling the vehicle closure; software
executable by the processor, the software configured to generate a
pulse width modulation generated drive signal in response to the
generated drive signal; and an input/output unit configured to
communicate the pulse width modulation generated drive signal to
the drive mechanism for providing dynamic braking to the vehicle
closure.
[0017] In one embodiment, the controller may include a first
microcontroller circuit operable between an on position and an off
position, the first microcontroller circuit in contact with a power
source for providing an opening drive signal to the drive
mechanism. The controller may also include a second microcontroller
circuit operable between an on position and an off position, the
second microcontroller circuit in contact with the power source for
providing a closing drive signal to the drive mechanism. The
controller may further include a third microcontroller circuit
operable between an on position and an off position, the third
microcontroller circuit for providing the pulse width modulation
generated drive signals. In another embodiment, the controller
includes a fourth microcontroller circuit operable between an on
position and an off position, the fourth microcontroller circuit in
contact with the controller for providing the dynamic braking to
the vehicle closure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] For a more complete understanding of the features and
advantages of the present invention, reference is now made to the
detailed description of the invention along with the accompanying
figures in which corresponding numerals in the different figures
refer to corresponding parts and in which:
[0019] FIG. 1A is an illustration of a perspective view of a
backend of a vehicle with a lift gate in an open position according
to an embodiment of the present invention;
[0020] FIG. 1B is an illustration of a perspective view of a
backend of the vehicle with a lift gate of FIG. 1A in a closed
position according to an embodiment of the present invention;
[0021] FIG. 1C is an illustration of a side view of a backend of a
vehicle with a lift gate in an open position according to another
embodiment of the present invention;
[0022] FIG. 1D is an illustration of a backend of the vehicle with
a lift gate of FIG. 1C in a closed position according to another
embodiment of the present invention;
[0023] FIG. 2 is a block diagram of an exemplary controller having
a processor executing software for driving a closure system
according to an embodiment of the present invention;
[0024] FIG. 3 is a schematic diagram of a control circuit according
to an embodiment of the present invention;
[0025] FIG. 4 illustrates a graph of Hall Pulse Period and PWM duty
cycle versus position of a conventional control system attempting
to control with constant speed the closing of a gate without
dynamic braking;
[0026] FIG. 5 illustrates a graph of Hall Pulse Period and PWM duty
cycle versus position with dynamic braking according to an
embodiment of the present invention;
[0027] FIG. 6 illustrates a flow diagram for an exemplary process
for controlling a PWM signal for driving and braking a motor of a
vehicle closure according to an embodiment of the present
invention; and
[0028] FIG. 7 illustrates a flow diagram for an exemplary process
for controlling a PWM signal for driving and braking a motor of a
vehicle closure according to another embodiment of the present
invention.
DETAILED DESCRIPTION OF THE DRAWINGS
[0029] Referring to FIGS. 1A-1D (collectively FIG. 1) are
illustrations of a backend of a vehicle 102 with a vehicle closure,
such as lift gate 106, in an open and closed position using the
dynamic braking system 100. Vehicle 102 includes a vehicle body 104
and lift gate 106 coupled to vehicle body 104 by a hinge 108 or
other mechanical fastening device or apparatus, rotatable or
otherwise, that enables lift gate 106 to be opened and closed as
desired. Dynamic braking system 100 further includes a controller
110 that may be mounted on vehicle 102. A drive mechanism, such as
a motor 112, may be mounted on vehicle 102 and may be electrically
coupled to controller 110. In one embodiment, motor 112 is mounted
on vehicle 102 such that it is in direct mechanical contact with or
is embodied within or a part of an actuator 116. Motor 112 may have
electrical contacts or connectors 114 for being electrically in
communication or contact with controller 110 to receive a drive
signal for controlling operation of motor 112. Although motor 112
is shown and described in FIG. 1, it should be understood that the
principles of the present invention may be applied to any drive
mechanism, such as an electrical motor or electromechanical motor,
which is capable of generating an electrical drive signal
("generated drive signal") during at least a portion of the closing
operation of the vehicle closure. Reference to motor 112 is for
exemplary purposes and constitutes one of many possible
embodiments, configurations, and applications in accordance with
the principles of the present invention. Additionally, while the
principles of the present dynamic braking system are being
described with regard to vehicle 102, it should be understood that
these same principles may be applied to motors other than those
used on vehicles. For example, the principles of the present
dynamic braking system may be applied to motors used on boats,
airplanes, buildings (e.g., automatic doors), or any other motor
used for controlling operation of a mechanical device or structure.
These principles may be applied to both direct current ("DC") or
alternating current ("AC") motors, as well as coils where both
terminals return to a microcontroller.
[0030] In one embodiment, motor 112 is capable of generating a
drive signal 132 during the closing operation of lift gate 106. As
further described below, motor 112 generates an drive signal 132
during at least a portion of the closing operation in response to
the kinetic force of lift gate 106 being closed and transmits this
drive signal from motor 112 to controller 110, which is then fed
back to motor 112 to be used by motor 112 to counter the closing
force of lift gate 106. In this manner, no additional drive signal
is required for operating motor 112 in providing a counter force to
the closing lift gate 106.
[0031] In one embodiment, dynamic braking system 100 may include an
actuator 116, such as a motorized strut for raising and lowering
lift gate 106. In one aspect, actuator 116 may include motor 112
and be the same unit. In another aspect, actuator 116 may be a
separate unit from motor 112, in which case connectors (not shown)
may connect motor 112 to actuator 116. Motor 112 and/or actuator
116 are in communication with controller 110 via connectors 114.
Actuator 116 may provide linear and/or non-linear motion control of
lift gate 106 for opening and closing lift gate 106 during
operation of dynamic braking system 100. In addition, dynamic
braking system 100 may further include a gas spring or strut 118
(not shown in FIG. 1C) to provide additional mechanical energy or
force for opening and closing lift gate 106. In one aspect,
actuator 116 or dynamic braking system 100 may provide variable
speed control for the opening and closing operations of lift gate
106. Gas spring 118 may be mounted between the vehicle body 104 and
lift gate 106, for example.
[0032] Dynamic braking system 100 may further include a vehicle
closure position sensor to determine the distance between lift gate
106 and vehicle body 104 during opening and closing operations. Any
of several types of these vehicle closure position sensors may be
employed. For example, in one embodiment, a rotary flex shaft
encoder 122 may be mounted to hinge 108 for determining the
distance between lift gate 106 and vehicle body 104. As lift gate
106 opens or closes, hinge 108 rotates, thereby causing rotary flex
shaft encoder 122 to rotate and generate a digital pulse or pulse
width modulation ("PWM") signal. Rotary flex shaft encoder 122 may
be electrically coupled to controller 110 and the signals produced
by rotary flex shaft encoder 122 in response to lift gate 106
opening and/or closing may be communicated to controller 110. In
one embodiment, rotary flex shaft encoder 122, may be mounted to
vehicle body 104 (e.g., lift gate 106 and/or hinge 108) of vehicle
102. Although FIG. 1 shows and describes a lift gate 106, it should
be understood that the principles of the present dynamic braking
system 100 applies to vehicle closure or any closure system, such
as rotational closure systems, trunks, lift gates, tailgates,
tonneau covers, engine covers, hospital beds, tanning bed covers,
compartment doors, dump beds, and the like. Reference to lift gate
106 is for exemplary purposes and constitutes one of many possible
embodiments, configurations, and applications in accordance with
the principles of the present dynamic braking system 100. In
addition, rotary flex shaft encoder 122 may also be located at
another position on vehicle body 104, such as coupled to lift gate
106 away from hinge 108. Also, it should be understood that any
type of angle sensor may be positioned and employed by dynamic
braking system 100, such as an analog angle sensor.
[0033] In another embodiment, a Hall effect sensor 124 may be used
to determine the distance between lift gate 106 and vehicle body
104. Hall effect sensor 124 may be mounted on motor 112, a
mechanical drive train associated with actuator 116 and/or motor
112, or is located in another location on vehicle 102. Signals from
Hall effect sensor 124 are generated by the opening and/or closing
of lift gate 106 relative to vehicle body 104 of dynamic braking
system 100. Hall effect sensor 124 determines the position and/or
speed of lift gate 106 relative to vehicle body 104. Hall effect
sensor 124 may be in communication with controller 110 via
connectors 120 and signals produced in response to lift gate 106
opening and/or closing may be communicated to controller 110 via
connectors 120. Additionally, Hall effect sensor 124 may be used to
detect a change in velocity and to allow for speed control and
obstacle detection.
[0034] Dynamic braking system 100 may further include a remote
keyless entry ("RKE") transponder/keyfob 126 for transmitting
wireless signals 130, such as radio frequency or infra-red
radiation signals, to controller 110 for opening and closing lift
gate 106. Additionally, transponder/keyfob 126 may transmit
authorization codes 128 for accessing one particular dynamic
braking system 100 in a particular vehicle 102 over another as is
in known in the art. Controller 110 may include a RKE antenna (not
shown), for providing functionality to transponder/keyfob 126. When
a button is pressed on transponder/keyfob 126, the appropriate
message (i.e. "open liftgate" or "close liftgate") is sent from
transponder/keyfob 126 via UHF RF signals, for example, where it is
received by controller 110 at vehicle 102. Controller 110 may
receive this information and in turn transmit a message across
connectors 114 instructing actuator 116 and motor 112 to react
accordingly. Dynamic braking system 100 further includes drive
signals and control signals (collectively or separately 132) that
are communicated via connectors 114 between controller 110 and
motor 112 for controlling motor 112.
[0035] FIG. 2 is an embodiment 200 of a block diagram of an
exemplary controller 110 having a processor 202 executing software
204. Processor 202 may be in communication with a memory 206 for
storing information, such as a program, software 204, and/or data
used by the program or software 204, for example, and an
input/output (I/O) unit 208. In one embodiment, encoder rotary flex
shaft 122 may generate an angle signal having a PWM form and/or
Hall effect sensor 124 may generate a signal relating to the
distance between lift gate 106 and vehicle body 104. I/O unit 208
may receive the signal and communicate it to processor 202 for
processing via software 204, for example. In the instance of the
rotary flex shaft encoder 122, the signal may be a digital PWM
signal. In addition, controller 110, software 204 and/or processor
202 may generate a drive signal and a compensation signal based on
the angle signal or distance signal to be utilized to alter the
drive signal for controlling velocity and sensing obstacles during
movement of lift gate 106 utilizing a position, velocity,
acceleration, and/or force controller, as further described below.
I/O unit 208 may be part of the processor 202 itself or be separate
electronic components configured to drive motor 112 to drive lift
gate 106 (FIG. 1) to a desired position.
[0036] Controller 110 may further include circuitry for dynamic
braking of a vehicle closure. FIG. 3 illustrates an embodiment 300
of a schematic of an exemplary circuit for dynamic braking of a
vehicle closure. Circuitry 300 may be configured to drive motor 112
in a forward direction, drive motor 112 in a reverse direction,
enable the motor 112 to freewheel when not being powered by the
dynamic braking system, and/or provide dynamic braking to motor
112.
[0037] Referring to FIGS. 1A, 1C, and 3, motor 112 may include a
first terminal 302a and a second terminal 302b (collectively 302)
for enabling voltages to be applied for controlling speed and
direction of motor 112. A first connector 114a and a second
connector 114b (collectively 114) are electrically connected to the
first terminal 302a and second terminal 302b, respectively, and
circuitry 300 of controller 110. In terms of being "at the motor,"
any circuitry or electrical device connected to either of the
connectors 114 and/or terminals 302, themselves, or motor 112
itself is considered to be at the motor.
[0038] Software 204 executed by controller 110 may also include
software that operates in conjunction with circuitry 300. A
controller bus (not shown) may be connected between controller 110
and circuitry 300 to enable communication of drive signals and/or
control signals 132 between controller 110, circuitry 300, and/or
motor 112. One or more control signals 132 may include one or more
signals to turn on and off switches controlled within controller
110. It should be understood that control signals 132 may be
digital or analog in accordance with the controller 110 and
circuitry 300. In one embodiment, controller 110 may include analog
input ports. Alternatively, an analog-to-digital ("A/D") conversion
device (not shown) may be utilized in conjunction with controller
110. Still yet, circuitry 300 may include an A/D conversion device
to communicate over the controller bus, for example.
[0039] To power dynamic braking system 100, including controller
110 and motor 112, a battery or power supply 306 of vehicle 102 may
be connected to one or more components of dynamic braking system
100. In normal operation, power supply 306 is utilized to power
(i.e., enable and disable) motor 112 as understood in the art.
Consistent with FIG. 2, the circuitry 300 is connected to motor 112
via the connectors 114.
[0040] In one embodiment, circuitry 300 of dynamic braking system
100 includes a first microcontroller port 308a, a second
microcontroller port 308b, a third microcontroller port 308c, and a
fourth microcontroller port 308d (collectively 308). Circuitry 300
of dynamic braking system 100 may further include first transistor
310a, second transistor 310b, first metal-oxide-semiconductor
field-effect transistor ("MOSFET") 310c, second MOSFET 310d, and
third transistor 310e (collectively 310). Further, circuitry 300 of
dynamic braking system 100 may also include first relay 312a,
second relay 312b, and third relay 312c (collectively 312). The
relays 312 may be any type of relays 312 commonly know in the art.
They may be controlled by an analog or digital output from
controller 110.
[0041] Circuitry 300 of dynamic braking system 100 may also include
first resistor 314a, second resistor 314b, and third resistor 314c
(collectively 314). In one embodiment, first relay 312a and second
relay 312b are in communication with pin 316a, pin 316b, pin 316c,
pin 316d, pin 316e, and pin 316f (collectively 316); and third
relay 312c is in communication with pin 316g, pin 316h, and pin
316i (collectively 316). As described above, dynamic braking system
100 provides forward direction, reverse direction, freewheeling,
and dynamic braking functionality for opening and closing lift gate
106 of vehicle 102. By switching through these different modes
during operation, dynamic braking system 100 provides enhanced
speed control and obstacle detection to the operation of lift gate
106 by reducing reaction time and managing efficiently and
effectively the energy within the present dynamic braking system
100.
[0042] First microcontroller port 308a may drive motor 112 in a
first or forward direction by turning on first transistor 310a
which energizes a coil of first relay 312a to activate first relay
312a. This connects a pin 316a to power supply 306 through pin
316e. Software 204 in controller 110 causes second microcontroller
port 308b to shut off, thus causing second transistor 310b and
second relay 312b to be deactivated. In this embodiment, fourth
microcontroller port 308d is turned on that activates third relay
312c, thus connecting pin 316g of third relay 312c to pin 316h of
third relay 312c. In one aspect, third microcontroller port 308c
pulse width modulates first MOSFET 310c and second MOSFET 310d to
control the speed of motor 112. This causes motor 112 to operate in
a first or forward direction, thus moving lift gate 106 in a first
or forward position to an open position as shown in FIGS. 1A and
1C.
[0043] With further reference to FIG. 3 and as discussed above,
dynamic braking system 100 also provides control of lift gate 106
in a second or reverse direction. In this aspect, first
microcontroller port 308a is shut off, and as a result first
transistor 310a and first relay 312a are deactivated. Second
microcontroller port 308b is activated, which turns on second
transistor 310b that energizes the coil of second relay 312b, thus
activating second relay 312b. This action causes pin 316b of second
relay 312b to connect to power supply 306 through pin 316f. Fourth
microcontroller port 308d is turned on, which activates third relay
312c, thus connecting pin 316g of third relay 312c to pin 316h of
third relay 312c. Third microcontroller port 308c pulse width
modulates first MOSFET 310c and second MOSFET 310d to control the
speed of motor 112. In either direction, opening or closing,
MOSFETs 310C and/or 310D operate to in part drive the circuit for
opening or closing lift gate 106, as further described herein.
[0044] With continuing reference to FIG. 3, dynamic braking system
100 may further provide freewheeling functionality to motor 112 for
manually operating lift gate 106 by a user if desired. Generally,
freewheeling is the ability for motor 112 to turn freely when not
being powered or energized by dynamic braking system 100. This may
be desirable in operations when a manual mode is required or wanted
in addition to a powered lift gate 106. In this aspect, dynamic
braking system 100 does not provide power to circuitry 300, thus
microcontroller ports 308 are shut off, and as a result first
transistor 310a, second transistor 310b, first MOSFET 310c, second
MOSFET 310d, and relays 312 are deactivated. This then enables lift
gate 106 to be manually operated without power being supplied to
motor 112.
[0045] As described above, dynamic braking system 100 further
provides a dynamic braking to motor 112. Dynamic braking harnesses
the energy generated by opening and/or closing lift gate 106 of
vehicle 102 and uses it to apply a braking force by dynamic braking
system 100 to slow it down without the addition of power to motor
112. In one aspect, first microcontroller port 308a, second
microcontroller port 308b, and fourth microcontroller port 308d are
turned off such that first transistor 310a, second transistor 310b,
third transistor 310e, and relays 312 are deactivated. To harness
the energy generated by motor 112 operating lift gate 106 in a
closing operation, third microcontroller port 308c pulse width
modulates first MOSFET 310c and second MOSFET 310d to provide the
desired speed control of lift gate 106. Depending on the direction
of travel of lift gate 106, forward or reverse, only one of first
MOSFET 310c or second MOSFET 310d works toward providing speed
control while the other of first MOSFET 310c and second MOSFET 310d
acts as a diode. Circuitry 300 may further include additional
functionality, such as filtering, clamping, and debouncing
functionality typically found in circuit design. In one embodiment,
motor 112 when driven becomes a generator and by shunting the
energy back to motor 112 it provides a negative energy back to
itself canceling out the energy generated. Controller 110 controls
how much of the energy is shunted back to motor 112 by PWM.
Further, controller 110 manipulates and manages the energy it
receives from the dynamic braking, but controller 110 itself is
powered by the power supply 306 of the vehicle 102.
[0046] The configuration of circuitry 300 enables dynamic braking
at motor 112, as further described herein. It should be understood
that alternative embodiments of circuitry 300 may be utilized to
perform the same or functional equivalent testing of circuitry 300
of motor 112. Still yet, alternative electrical components may be
utilized and/or different values of the electrical components may
be used in accordance with the principles of the present dynamic
braking system.
[0047] Generally, the period of the pulse has an inverse relation
to the velocity of lift gate 106; the greater the pulse period, the
slower lift gate 106 is traveling or moving. For example, two
different ranges of pulse periods, 0 to 100 and 100 to 250, may be
used. In this example, between pulse position 250 and dynamic
braking system 100, the set point may be 30 milliseconds ("ms") and
between the pulse position 100 and pulse position 0, the set point
may be 40 ms. To show the differences between conventional control
systems and the present dynamic braking system, FIG. 4 illustrates
a graph 400 of a conventional system controlling the closing of a
gate and FIG. 5 illustrates a graph 500 of the present dynamic
braking system controlling the closing of gate, such as lift gate
106. FIG. 4 illustrates a graph 400 of a Hall Pulse Period &
PWM duty cycle versus position in a situation where a conventional
control system does not apply dynamic braking to a motor. As a gate
transitions from fully open (pulse position 250) to closed (pulse
position 0), a control unit adjusts the drive PWM signals 402 in an
attempt to keep a gate closing at a constant speed as shown by
pulse period 404. In the first region of travel (250-100), a
conventional control system strives to maintain a pulse period of
30 ms, for example. Once entering the second region of travel
(100-0), the travel dynamics of the gate change as gravity assists
the gate closure, and a conventional control system has a hard time
maintaining a pulse period of 40 ms. The drive PWM signals 402
adjusts to maintain a pulse period of 40 ms, but as the gate begins
to close rapidly due to gravity, a conventional braking system
cannot adapt fast enough and the gate slams closed.
[0048] FIG. 5 illustrates a graph 500 of the present dynamic
braking system controlling the closing of gate dynamically, such as
lift gate 106. As lift gate 106 transitions from fully open (pulse
position 250) to closed (pulse position 0), controller 110 adjusts
the drive PWM signals 502 to keep lift gate 106 closing at a
constant speed as shown by pulse period 504. In the first region of
travel (250-100), dynamic braking system 100 maintains a pulse
period of approximately 30 ms, for example. Once entering the
second region of travel (100-0), the travel dynamics of lift gate
106 changes as gravity assists the lift gate 106 closure. As can be
seen in FIGS. 4 and 5, there is little differences for the first
approximate 200 pulses of travel between the conventional system of
FIG. 4 and dynamic braking system 100 as shown in FIG. 5. For the
first approximate 200 pulses dynamic braking by, the present
dynamic braking system 100 has not been activated. In one
embodiment, at an approximate pulse period of 50, dynamic braking
system 100 is engaged, as shown by brake PWM signal 506. During
this time there is no additional power added to motor 112 by
controller 110, as seen by drive PWM signals 502. Dynamic braking
system 100 uses the generated drive signals generated by motor 112
under mechanical force from kinetic energy by lift gate 106 during
its fall or closing operation and feeds it back into dynamic
braking system 100 to slow itself down. As a result, controller 110
is closer to maintaining its target pulse period of 40 ms and lift
gate 106 does not slam closed. Additionally, the present dynamic
braking system 100 may support the opening of lift gate 106 as
well.
[0049] In addition to the aforementioned aspects and embodiments of
the present dynamic braking system 100, the present dynamic braking
system further includes methods for dynamically braking the closing
of a vehicle closure, such as lift gate 106. FIG. 6 illustrates a
flow diagram of an embodiment 600 of one such process. Process 600
describes how PWM is controlled by controller 110, software 204,
and/or circuitry 300 to drive and dynamically brake lift gate 106
during closure. The control process 600 starts at step 602. At step
604, an inquiry is made whether dynamic braking is already being
provided by controller 110, software 204, and/or circuitry 300. If
the answer to this inquiry is "no," then at step 606 controller
110, software 204, and/or circuitry 300 of dynamic braking system
100 control motor 112 by PWM as described herein. This step may
include controller 110, software 204, circuitry 300, and/or power
supply 306 providing a conventional PWM signal to motor 112.
[0050] At step 608, an inquiry is made whether lift gate 106 is
being closed too quickly. If the answer to this inquiry is "no,"
then at step 610 controller 110, software 204, circuitry 300,
and/or power supply 306 of dynamic braking system 100 increase the
PWM signal by proportion based on information received by
controller 110, software 204, and/or circuitry 300. In one
embodiment, at step 608, dynamic braking system 100 may determine
whether lift gate 106 is being closed too quickly by receiving data
regarding the speed and/or position of lift gate 106 through rotary
flex shaft encoder 122 and/or Hall effect sensor 124. For example,
an angle signal having a PWM or analog form with a duty cycle based
on the angle of lift gate 106 may be generated at step 608. The
angle signal may be fedback to controller 110 at step 608.
Additionally, controller 110 may utilize a position and/or speed
control algorithm as understood in the art.
[0051] If the answer of the inquiry at step 604 is "yes," then
dynamic braking system 100 makes another inquiry whether the
closing rate of lift gate 106 is too fast. If the answer to this
inquiry is "no," then at step 614 controller 110, software 204,
and/or circuitry 300 of dynamic braking system 100 decrease the
braking PWM signal supplied to motor 112. At step 616, an inquiry
is made whether dynamic braking should be turned off. If the answer
to this inquiry is "yes," then at step 618 a driving cue counter is
incremented. A braking cue counter may reside in software 204 that
may provide a delay that provides software 204 enough time to
determine if regular speed control is not capable of controlling
the speed of lift gate 106 during closing or opening. For example,
if the counter reaches a certain level, then the dynamic braking is
turned on. Similarly, a driving cue counter of the dynamic braking
system 100 no longer may determine if dynamic braking is no longer
needed, thus transitioning back to regular speed control.
[0052] If the answer to the inquiry at step 612 is "yes," then at
step 620 dynamic braking system 100 increases the braking PWM
signal, such as increasing the PWM to dynamic braking system up to
100%, full braking. Referring back to step 608, if the answer to
the inquiry is "yes," then at step 622 dynamic braking system 100
decreases the PWM signal by proportion based on information
delivered by the speed algorithms of dynamic braking system 100,
rotary flex shaft encoder 122 and/or Hall effect sensor 124. At
step 624, an inquiry is made whether the PWM signal is at the
minimum range or setting. If the answer to this inquiry is "yes,"
then another inquiry is made at step 626 whether lift gate 106 is
still closing too fast. If the answer to both steps 624 and 626 are
"no," then the process 600 returns to step 604. If the answer to
the inquiry at step 626 is "yes," then at step 628 the braking cue
counter is incremented.
[0053] In addition to the process 600 described above, dynamic
braking system 100 further includes a process for checking the
status of the dynamic braking and turning the dynamic braking on or
off. FIG. 7 illustrates a flow diagram of an embodiment 700 of one
such process. The process 700 starts at step 702. At step 704, an
inquiry is made whether the braking cue counter is at its limit. If
the answer to this inquiry is yes, then at step 706 all relays,
such as relays 312 are turned off or deactivated, thus initiating
or engaging dynamic braking of motor 112. At step 708, dynamic
braking system 100 adjusts the PWM value for offsetting a drive
signal to a braking signal. At step 710, dynamic braking of motor
112 is performed.
[0054] Returning to step 704, if the answer to this inquiry is
"no," then at step 712 an inquiry is made whether the driving
signal cue counter is at its limit. If the answer to this inquiry
is "yes," then at step 714 dynamic braking system 100 turns on
relays 312 to engage motor 112 in a forward or reverse direction.
At step 716, the value of the PWM signal is adjusted for offset
from a braking operation to a drive operation. At step 718, the
dynamic braking by dynamic braking system 100 is turned off or
deactivated.
[0055] In addition to these steps above, the present dynamic
braking system may further inquire as to whether a latch for
maintaining the lift gate is closed. If the latch is not closed,
then controller 110, software 204, and/or circuitry 300 may run a
procedure to close the lift gate. If it was determined at that the
latch is closed, then the controller 110, software 204, and/or
circuitry 300 may begin an open lift gate procedure as described
above.
[0056] Further, in addition to the steps above, the present dynamic
braking system may further inquire whether the speed or velocity of
lift gate 106 is less than an obstacle threshold. If the speed of
lift gate 106 is less than the obstacle threshold, then an obstacle
is detected to be obstructing movement of lift gate 106. The lift
gate may be released to a manual control, and motor 112 moving lift
gate 106 may be stopped or reversed to avoid damage to the
obstacle, injury to a person, or damage to the lift gate or its
drive system.
[0057] The previous detailed description is of a small number of
embodiments for implementing the invention and is not intended to
be limiting in scope. One of skill in this art will immediately
envisage the methods and variations used to implement this
invention in other areas than those described in detail. The
following claims set forth a number of the embodiments of the
invention disclosed with greater particularity.
* * * * *